Recently, component analysis using visible and/or near-infrared light irradiated on a given sample to determine the wavelength or wavelength range absorbed by specific components in that sample has been conducted in various fields to determine the characteristics of those specific components.
Such a process is achieved by injecting a sample into a quartz cell, then irradiating the cell with visible and/or near-infrared light in the wavelength range of 400 nm to 2500 nm and using the near-infrared spectrograph (e.g. NIRSystem 6500 manufactured by Nireco Co.), and then analyzing the transmitted light and the reflected light, or transmitted/reflected light (henceforth referred to as transmitted/reflected light).
Generally, near-infrared light is a low-energy magnetic wave which means that the use of such a low-energy magnetic wave does not alter nor damage the basic characteristics of the materials or sample under scrutiny.
Therefore, relevant information can directly and immediately be obtained by detecting the spectral intensity of transmitted and reflected light and conducting multivariate analysis by using absorption rate data.
Already disclosed, is the method of getting sample information by consecutively obtaining multiple spectra from light irradiation in the wavelength range of 400 nm to 2500 nm and/or a wavelength suitable to obtain the needed data for a specific sample. After the sample is irradiated, multivariate analysis of the water molecule peaks allows identification of the elements and provides the basis for the construction of model. (Patent document 1)
Furthermore, multivariate analysis of the absorbance rate data of visible and/or near infrared light in water molecules provides a method for measuring the presence of somatic cells in raw milk and, as a result, becomes an additional means of diagnosing mastitis in cows (Ref. e.g. Patent Document 2).
Patent document 1: Japanese Published Unexamined Application 2002-5827 (Pages 1 to 9, FIG. 1)
Patent document 2: International Publication WO01/75420 (Pages 1 to 5, FIG. 1)